Forming and joining of commercial steel grades in the semi-solid state

Kopp, Reiner; Kallweit, Jens; Möller, Thorsten; Seidl, Ingold

doi:10.1016/s0924-0136(02)00766-5

Cited by 59 publications

(48 citation statements)

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“…A similar process, on a larger scale, is joining dissimilar materials at the semi-solid range, giving as results a diffusive layer between the materials. [80][81][82] Recently, Cure 83 has shown the possibility of semi-solid processing of materials without the temperature interval between the solidus and the liquidus (e.g. pure binary eutectics and pure metals).…”

Section: Further Development Of Ssmmentioning

confidence: 99%

Critical assessment: Opportunities in developing semi-solid processing: Aluminium, magnesium, and high-temperature alloys

Rogal

2017

Materials Science and Technology

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Semi-solid metal processing (SSM) is a modern metal forming technology offering net-shape metal components of complex geometry in a one-step operation. The process relies on the thixotropic behaviour of metals with non-dendritic microstructures in a wide semi-solid temperature range. The beneficial effects are currently exploited in aluminium and magnesium alloys. This alternative manufacturing route to casting and forging has generated high expectations regarding high melting alloys, although no conclusive results have been achieved so far. Current studies focus on a deep understanding of the fundamental basics of alloys in the semisolid range, e.g. rheology, microstructural evolution, and the consequences of forming, e.g. relations between process parameters, microstructure, and properties. This critical assessment aims at defining the important needs for further development of SSM, and assessing current knowledge.

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Section: Further Development Of Ssmmentioning

confidence: 99%

Critical assessment: Opportunities in developing semi-solid processing: Aluminium, magnesium, and high-temperature alloys

Rogal

2017

Materials Science and Technology

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“…The use of protective atmospheres has also been adopted by other authors in order to avoid excessive high temperature oxidation [12,13].…”

Section: Partial Remelting Experimentsmentioning

confidence: 99%

Thixoforming of a high performance HP9/4/30 steel

Omar

Palmiere

Howe

et al. 2005

Materials Science and Engineering: A

100

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Thixoforming is a forming process that shapes metal components in their semisolid state. Prior to forming, the microstructure of the alloy consists preferably of solid metal spheroids in a liquid matrix, which can be difficult to achieve with hot-worked, high alloy steels prone to strong microsegregation bands. A high performance HP9/4/30 steel has been assessed for thixoformability through a direct remelting route. Partial remelting was carried out between 1430 and 1470 o C. Liquation occurred initially at grain boundaries, then also along the segregation bands. With increasing time and hold temperature, these "columns" broke down into shorter, more equiaxed segments, offering more chance of being thixoformed. Successful thixoforming producing netshape demonstrator parts was achieved at processing temperatures in the range of 1470 -1480°C, which corresponds to approximately 50 to 80% liquid (based on Differential Thermal Analysis). A thin solid skin, formed on the surface of the slug as a result of heat loss, had prevented the slug from collapsing. The resulting thixoformed products are discussed in relation to their load-displacement signals.

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“…However, these tool materials fail to sustain the severe conditions encountered when thixoforming higher melting point alloys such as steels. [3][4][5][6][7] Thermal fatigue, combined with the erosive wear due to abrasion and impact of the already solid particles in slurries and high-temperature oxidation, renders the conventional hot work tool steels entirely inadequate. [7][8][9][10][11] While a number of suitable replacements were identified in recent years, [10,[12][13][14][15][16][17][18][19][20][21][22][23][24] cost considerations favor coating hot work tool steels over employing high-temperature alloys for tooling applications.…”

Section: Introductionmentioning

confidence: 99%

Thermal Fatigue Testing of Plasma Transfer Arc Stellite Coatings on Hot Work Tool Steels under Steel Thixoforming Conditions

Birol

Kayihan

2010

Metall Mater Trans A

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The thermal fatigue performance of Stellite 12 coating deposited on X32CrMoV33 hot work tool steel via the plasma transfer arc (PTA) process was investigated under steel thixoforming conditions. Stellite 12 coating has made a favorable impact on the thermal fatigue performance of the X32CrMoV33 hot work tool steel. The latter survived steel thixoforming conditions lasting much longer, for a total of 5000 cycles, when coated with a PTA Stellite 12 layer. This marked improvement is attributed to the higher resistance to oxidation and to temper softening of the Stellite 12 alloy. The Cr-rich oxides, which form during thermal cycling, provide adequate protection to high-temperature oxidation. In contrast to hot work tool steel, Stellite 12 alloy enjoys hardening upon thermal exposure under steel thixoforming conditions. This increase in the strength of the coating is produced by the formation of carbides and contributes to the superior thermal fatigue resistance of the Stellite 12 alloy. When the crack finally initiates, it propagates via the fracture of hard interdendritic carbides. The transformation of M 7 C 3 to M 23 C 6 , which is more voluminous than M 7 C 3 , promotes crack propagation.

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Forming and joining of commercial steel grades in the semi-solid state

Cited by 59 publications

References 1 publication

Critical assessment: Opportunities in developing semi-solid processing: Aluminium, magnesium, and high-temperature alloys

Critical assessment: Opportunities in developing semi-solid processing: Aluminium, magnesium, and high-temperature alloys

Thixoforming of a high performance HP9/4/30 steel

Thermal Fatigue Testing of Plasma Transfer Arc Stellite Coatings on Hot Work Tool Steels under Steel Thixoforming Conditions

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